Transfer press

ABSTRACT

A TRANSFER PRESS COMPRISES A PAIR OF SPACED PILLARS WHICH SUPPORT A BEAM, RAM-SLIDE AND BED. THE BEAM SUPPORTS A MAIN SHAFT PROVIDING CAMS FOR MOVING RAMS AND HAS IN ITS LOWER PORTION A PLURALITY OF SHAFT SUPPORTERS. THE RAM-SLIDE SLIDABLY SUPPORTS EACH OF THE RAMS IN PERFECT INDEPENDENT RELATIONSHIP WITH THE ADJACENT RAMS SO AS TO PREVENT EACH RAM FROM BEING SUBJECTED TO OBJECTIONABLE INFLUENCES DUE TO THE MOVEMENT OF THE OTHER RAMS.

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Filed July 24, 1968 4 sheets-sheet /1 United States Patent O U.S. Cl.72-404 2 Claims ABSTRACT F THE DISCLOSURE A transfer press comprises apair of spaced pillars which support a beam, ram-slide and bed. The beamsupports a main shaft providing cams for moving rams and has in itslower portion a plurality of shaft supporters. The ram-slide slidablysupports each of the rams in perfect independent relationship with theadjacent rams so as to prevent each ram from being subjected toobjectionable influences due to the movement of the other rams.

The present invention relates to a transfer press by which several stepsof pressing operation are carried out with one press.

At present, there is a tendency that the plastic working by presses isever progressively developed because of various advantages With respectto speed of operation and economical use of material and labour. In casewhere a desired working operation is not completed by one heating,namely in one step, several steps of operation are generally carried outto obtain desired products. In this case, there are two methods, oneemploying several presses each of which performs one step, and the otherin which one press is provided with dies for several steps each of whichis successively driven into pressing action to accomplish the pressingoperation. Either of these methods has merits and demerits of its own,and in some cases the conventional method of pressing can no longer meetthe need of the modern society that every product should be providedwith improved precision and quality.

In general, great pressing force is essential in presses. In order toobtain products of desired high precision, it is necessary to improvethe plasticity of the material in the dies. For this purpose,substantial increase of the compressive force and uniformity in thedimensions of the products must be effected, so that there arises anecessity to step up the pressing force to such an extent that it is byfar superior to the resistance created in working the material. Thegreat pressing force is also indispensable in manufacturing productswhich are smooth and pleasant to the touch. The strength of the pressand the pressure to be exerted thereby should, therefore, be severaltimes as great as those of conventional apparatuses so far designed andput to use. It should also be provided with rigidity which keeps themachine free of the stress to be produced the moment the workingoperation is performed.

The above mentioned two methods will be studied with respect to thepressing operation comprising several steps. It will be understood thata system for carrying out several successive steps of pressing operationcomprising several presses providing die for the respective stepsrequires a large installation costaud wide area with substantial lossinvolved in the transference of the materials and products, so that themanufacturing cost per product becomes inevitably great. In case of theother system in which working operation is successively performed bydies mounted on a press for several steps, a relatively large type ofpress must be employed which has spaced Wide enough to provide a numberof dies.

3,557,600 Patented Jan. 26, 1971 A press generally comprises an upperdie and lower die, and the material is placed into the lower die andpressed by the upper die thereby a large pressure being exerted withinthe enclosed dies. It is required that the pressure applied on thematerial be in the range of 50 to 60` kg./ mm.2 for hot working at atemperature of 1200o C.y and in the range of 250 to 300 kg./mm.2 forcold working at a temperature of 5 to 20 C. In case of products having asize of 50 mm. square, the required pressing pressure ranges 125 to 150t. in hot working at a temperature of 1200 C. and 600 to 750 t. in coldworking. In case of products of a size of mm. square, the pressurerequired is between 500 and 600 t. for hot working, between 2500 and3000 t. for cold working.

In a press comprising a lower bed and eccentric shaft, pressing forceexerted by a crank or cam mounted on a main shaft is utilized, while ina press employing a mechanism of fluid pressure such as oil pressure, acylinder and an upper laterally supported beamlike structure apply thepressing force therebetween for the operation. Accordingly, it isrequired that the main shaft, beamlike structure, bed and the like abovedescribed should have rigidity and strength great enough to prevent theflexure resulting from the pressing force. However, the longer the spanof the lateral shaft and beamlike structure, the smaller their strengthbecomes proportionally therewith. In other words, in order to provide alonger span, the press should be built in a large size structure. Themanufacturing cost of a press rises substantially in proportion to thethird or fourth power of the rate of increase in the length of the span.Furthermore, the pressure produced by the crank, cam or oil pressure isof a nature that it concentrates on the central point, so that when theresistance of the applied pressure is deflected off the center, theelements of the machine will be damaged and the precision will bemarkedly deteriorated. To solve this problem, it was conventionallycontemplated that a double crank or two cylinders were installed inseries, or the ram-slide was elongated, or the slide was provided acrossthe shaft. However, these could not perfectly preclude the abovementioned defects. That is, in accordance with the conventionaltechnique, the principle of carrying out each step by one die and onepress was considered to be the best method conceivable.

An object of the present invention is to provide a transfer press whichis capable of performing several steps of pressing operation by onepress and which is free of the disadvantages attendant to conventionalpresses. In more detailed description, an object of the presentinvention is to provide a transfer press which has rams for respectivelyand independently performing several steps of pressing operations, eachof the rams being adapted to perform the pressing operation in itscentral portion as if in a single press, without being subjected toobjectionable effects such as inclination, deflection or displacementdue to the movement of the other rams notwithstanding concurrentlyperformed pressing operations, whereby several steps of pressingoperation are continuously carried out in seriatim without damage beingcaused to the dies or the precision of the products being deteriorated.

Another important object of the present invention is to provide a noveltransfer press quite compact in overall structure in which wide spacesare provided between respective dies by dispensing with pillars or thelike for supporting the main shaft between each of the rams disposed inseries, thereby facilitating the installation of the devices such as forfeeding materials to respective dies, discharging the workpiecestherefrom and delivering them therebetween, the main shaft beingprovided with a structure capable of satisfactorily maintaining itsrigidity and strength.

Other objects and advantages of the present invention will be understoodfrom the detailed description with reference to the accompanyingdrawings, in which:

FIG. l is a front view partly in cross section showing a transfer pressin accordance with the present invention;

FIG. 2 is a view in vertical section taken along the line A-A in FIG. lshowing the transfer press of the present invention;

FIG. 3 is a side elevation of a side pillar in the transfer press inaccordance with the present invention;

FIG. 4 is a view in vertical section taken along the line B-B in FIG. 3showing the side pillar in the transfer press of the present invention;

FIG. 5 is a front view of a beam portion in the transfer press inaccordance with the present invention;

FIG. 6 is a side elevation of the beam portion; and

FIG. 7 is an enlarged view in section of principal parts showing a modeof carrying out the pressing operation in accordance with the presentinvention.

Referring to FIGS. l and 2, pillars 1 and 1 are disposed in oppositeside portions of the machine and constitute the framework of theapparatus together with a beam 2, ram-slide 3 and bed 4. The beam 2 hasin the opposite end portions thereof protrusions 5 and 5 to be fittedinto the pillars 1 and 1, whereby it is tightly inserted into lateralholes 6 and 6 in the pillars 1 and 1, the beam thereby being adapted towithstand the resistance attributable to the pressing force of the pressand complicated load such as iiexure, torsion and the like. The beam 2is also provided with a number of intermediate shaft supporters 7 in thelower portion thereof, the supporters together with supporters 8 and 8formed in the protrusions 5 and 5 supporting a main shaft 10 for movinga number of rams 9 upward and downward. The main shaft 10, inparticular, is supported by the supporters, short spans thereby beingdefined with each of cams 11 of the main shaft 10 disposed respectivelybetween the adjacent supporters. The main shaft is therefore preventedfrom fiexure and bending against the pressing resistance of a pluralityof rams 9 to satisfactorily ensure the dimensions and precision of theproducts.

The rams 9 are vertically slidably fitted into holes 20 formed in aram-slide 3. The upper surfaces of the rams are engaged through dovetailgrooves 22 with cam receivers 21 movably only in rearward and forward,the cam receivers 21 being adapted to be moved by the cams of the mainshaft 10. A portion of each ram 9 extends upward and is connected witheach 0f secondary cylinders 23 which is provided in the front portion ofthe beam 2. The secondary cylinders serve to assist the verticalmovement of the rams 9.

The bed 4 has grooves 12 for mounting lower dies 28 in the upper surfacethereof and internally pushers 14 providing pushing-up bars 13 forpushing up the worked products off the lower dies for discharge. Bymeans of connecting rods 15, the pushers 14 are operatively connected toa crank disc 16 and adapted to be actuated into upward and downwardmovement upon rotation of the crank disc. The bed, beam 2, ram-slide 3are firmly fitted into cut-out recessed portions 17, 18 and 19 formed inthe pillars 1 and 1, the juncture being connected by such means as boltsor welding.

Now, a motor M drives, through a fiywheel 24 and a small gear 25, alarge gear 26, which further drives the main shaft in operativerelationship with a clutch mounted in the large gear and a brake 27provided on the opposite side of the main shaft 10. Through the rotationof the main shaft 10, the cams 11 are brought into rotation therebydownwardly pushing down the cam receivers 21 while they are being movedforward or rearward (the state shown in FIG. 2). Due to this, the rams 9are moved down, whereby upper dies 29 attached to the lower ends of therams and upper rams 28 fixed to the upper surfaccs of the bed 4 shapeproducts. Then the main shaft 10, half rotated, brings the cams 11 backto the starting 4 position, and the clutch is released and the brake 27is applied to return the unit to the state ready for the operation.

FIG. 7 shows a mode of pressing operation performed by a transfer pressin accordance with the present invention, the figure showing four stepsof the operation carried out simultaneously by urging down four rams 9A,9B, 9C and 9D simultaneously for the pressing work. In this example, amaterial, round bar C, is beaten into a disclike article C in the firststep; the workpiece is further forced to be pressed into an article D ofa desired shape in the second step; the article is then, in the thirdstep, cut into upper and lower two elements E and E to obtain a finishedproduct E which is in the shape of a ring as desired; and in the fourthstep the element E is subjected to the pressing operation to get thebottom thereof punched off, thereby another annular finished product Fbeing produced. The operation to transfer the material from the firststep to the next steps in succession is automatically carried out bymechanical feed means such as magic hands or the like during theintervals of the pressing operations, namely while the rams areelevated. At this time, since there are no obstacles like pillars in thespace between ramslide 3 and bed 4 in accordance with the presentinvention, feed means for performing delivery operation in the abovedescribed order can be readily installed.

In the third and fourth steps of the abovementioned, for the release ofthe pressed products from the punches, there are disposed work releasemembers 30 which, when the rams 9C and 9D are raised up, strike againstrelease pillars 31 downwardly extending from the ram-slide 3, therebyreleasing the products out of the engagement with punches 32.

From the foregoing description it 'will readily be understood that thetransfer press of the present invention has the following advantages.

In accordance with the invention the main shaft for vertically moving aplurality of rams is supported by the shaft supporters formed in thelower surface of the beam 2 provided between the pillars 1 and 1 and bythe supporters formed in the protruding portions of the opposite ends ofthe beam, the main shaft 10 in particular being supported by thesupporters thereby short spansl being defined, the cam portions of themain shaft 10 being so disposed as to be each positioned respectivelybetween the supporters, so that the main shaft 10 is prevented fromfiexure, bending and the like against the pressing resistance of anumber of rams, the dimensions and precision of the products therebybeing satisfactorily secured. By dispensing with the pillars and thelike for supporting the main shaft between each ram, the machine,compact as it is, can provide wide spaces between respective diesthereby facilitating the installation of the feed means for deliveringthe workpiece from one set of dies to another in the order of theoperations.

Furthermore, the ram-slide 3 supports a number of rams, each perfectlyindependently of the adjacent rams and without being subjected to theirinfluence, each being capable of performing pressing operation,perfectly free of the influence such as inclination deflection, slippageor displacement due to the simultaneous pressing operation of other ramsas if in an independent press. This is also an important characteristicof the transfer press of the present invention.

Since the beam 2 in the transfer press of the present inventionsupporting the main shaft 10 for bringing a plurality of rams intovertical reciprocating movement is joined to the pillars 1 and 1 byfitting the protrusions formed in the opposite end portions thereof intothe lateral holes in the pillars 1 and l, namely since the beam and thepillars are not integrally casted of the same material as conventionallydone, crack or some other damage which might be caused to theabovementioned juncture due to complex load on the beam such as exure,torsion or the like created upon pressing can be precluded, and thestrength of the material can fully be exhibited.

Thus in the transfer press of the present invention, strengthened frameprovides a plurality of rams each of which is equipped with dies in thecenter of the lower end as if each of the rams were an independentpress, the dies placed on the theoretical center line of the pressingforce essential to the pressing operation thereby being aligned with thecenter of the stress created in the working. Each of the rams isaccordingly perfectly ensured against the objectionable influences suchas inclination, displacement, or movement to be attributable to themovement of other rams in simultaneous operation and the eiects similarto those accomplished by a number of presses provided in series can bebrought about. -In addition, by dispensing with 'the obstacles such aspillars and the like between respective rams, the transfer of thematerial between the steps can be facilitated.

It is a significant advantage of the present invention that, as apparentfrom the foregoing structure, the transfer press which is capable ofperforming several steps of pressing operation and in which the materialtransference is facilitated can be constructed of smaller amount ofmaterial in compact structure.

What we claim is:

1. A transfer press comprising a. pair of vertical pillars, a pluralityof rams provided between pillars, a ramslide provided between saidpillars, a main shaft provided with cams, a bed provided between saidpillars and a beam disposed between and supported by upper portions ofsaid pillars and supporting said main shaft, said beam being provided inthe opposite end portions thereof with protrusions for tting into saidpillars and said pillars have lateral holes of a shape mating with saidprotrusions, whereby said beam is tightly fitted in the lateral holes insaid pillars in secured connection therewith so that the connectingportions may be prevented from a crack or the like damage due to complexforce like ilexure and torsion to be exerted on said beam duringoperation of said press.

2. A transfer press as claimed in claim 1, wherein in the workingoperation to be performed by the cooperation of each upper die attachedto the lower end of each of said rams and each lower die attached to theupper surface'of said bed in corresponding relationship with said upperdie, said rams are so adapted that a material round bar may be beateninto a disc like article (C) by a rst ram, said article being furtherpressed into a workpiece in a desired shape (D) by a second ram, saidworkpiece being cut into two elements so as to obtain a finished product(E) of a desired annular shape by a third ram, the other element of saidcut off works being subjected to bottom punching-off operation by afourth ram so as to obtain another annular finished product (F).

References Cited UNITED STATES PATENTS 1,356,748 10/ 1920 Smith 72-4502,232,889 2/ 1941 Spencer 72-450 3,167,859 2/ 1965 Bailey 72-4053,289,450 12/1966 Clements 72-455 CHARLES W. LANHAM, Primary Examiner G.P. CROSBY, Assistant Examiner U.S. C1. X.R. 72-450, 455

